Keep track of your fitness around the clock with the Vivoactive 4S Smartwatch. Body Battery measures your body's energy reserves. The status of your energy level tells you when you're ready for your next workout. The Pulse Ox sensor measures blood oxygen saturation day and night, so you can see how well your body is absorbing oxygen. Discover whether you're having a calm, balanced, or strenuous day. Get reminders for short breathing exercises to help you relax. In the Garmin Connect app, you can log information about your cycle and physical and emotional symptoms. You can also learn about training and nutrition during the different phases of your cycle, gaining a better understanding of your body. Track how much fluid you consume daily. Set an automatic hydration goal that adjusts based on sweat loss during activities—even underwater. Get insights into the quality of your sleep across different phases (light, deep, REM) and receive blood oxygen saturation and respiratory data. If you want to relax or improve your focus, simply start a breathing exercise. The watch stores information about stress and breathing, helping you understand your breathing better. Highlights include wrist heart rate monitoring, animated workouts on the display, built-in sports apps, smart notifications, incident detection/emergency assistance, Garmin Pay, and the Connect IQ Store.